If you are an Android phone, you can first download an AmindPDF, which can edit, scan, convert, merge, split, read, etc. In short, it can meet all your needs for PDF. IOS and PC will be officially launched next month, so stay tuned.
I've tested the app with all the available PDF functions from the most popular scanners, and I've noticed no issues. If you are a pro in PDF processing or a developer, and you want to try the app, please contact me. I hope you like it.